1. Field of The Invention
The present invention relates to improvements to an apparatus for controlling a throttle valve electronically, such as an electronic motor, in an internal combustion engine.
2. Description of The Background Art
The previously known apparatus 1, as shown in FIG. 6, is installed in an intake air passage of an internal combustion engine, and the actuator 2 (such as an electronic motor) generates driving power on the basis of a driving signal of the control unit, which can open/close the throttle valve through the gear wheel transfer structure 3 and the axis 4 and related structure. The actuator can make an adjustment to the open angle of the throttle valve, which is separated from the accelerator operation of the driver. However, the actuator 2 is fixed on the flange 1B of the body 1A with a bolt 6. Thus, a one end supporting structure is used, which has the defects discussed below.
A one end supporting structure does not have enough anti-vibration control, and the actuator 2 is vibrated easily by the contrary rotation power on one end 2A side, which is the starting point. This problem could be reduced by making a heavy wall thickness of the flange and the body of the actuator 2, or increasing the strength of the internal structure of the actuator 2. However, this increases the weight, the size, and the cost.
Furthermore, the anti-vibration characteristics may be improved by fixing the free end 2B side of the actuator 2 (non-output side) on the case 1C of the body 1A with a press fit. But in this case, high accuracy may be needed to maintain the precision position to the gear wheel transfer structure 3. As a result, this may make assembly more difficult and increase the cost by a large amount.